How do I find out what's going on?

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How do I find out what's going on?

Post by Danny252 » Sat Nov 28, 2009 7:22 pm

Over the last week I've worked out quite reliably how to check on what the LHC is up to. This isn't a guide to deciphering displays - it's a guide to which ones to check to get an idea of what's happening right now without having to ask.

Check out the growing help pages and "What do the displays mean?" topic on the forum for how to read the information.

Page 1

This shows the current operator message, which can give valuable information on the day's objective, any faults, and tends to note if beams are likely to begin within an hour or so.

The Beam Permit flags, TDI and TED statuses all show if the LHC is prepared to accept a beam, or is already running one. See the Page 1 explanation image to see what these should be saying (and why) to allow a beam in.

I do NOT trust the Beam Intensity readings on Page 1. They fluctuate between 0 and random numbers a lot, even when the beam is supposedly stable.

Status Op

The Beam Intensity graph here is the best source for checking if beams are running. They show beams turning on, off and decaying in intensity as various things happen.

A glimpse at the status of each experiment can be gleamed here - ATLAS, ALICE, CMS and LHCb are the 4 main experiments, but LHCf and TOTEM statuses are also shown here.

Cryo Status

If any of it goes red, either something is overheating, or some software is misbehaving (this happened earlier this week, apparently).


Use the "authorisation" button to see the cryo statuses on top of the image. If it goes yellow/red, the same applies as above.

HOWEVER, ASC1 R4 (at point 4) has been red for a long time and no one seems too bothered.


Some information can be found here on what has happened recently, as well as possible plans.

LHCb Logbook

As well as LHCb-related stuff, the LHCb staff also record important Page 1 notices and Memos relating to LHC operational status. This is the best source to find out what's happened previously.

Google Group/Forum

Sometimes extra information, or an explanation of messages/problems, appears on these. Use them - and if you see something happen, report it!

Between those, you can usually work out what the LHC's current status is.

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Re: How do I find out what's going on?

Post by Xymox » Sun Nov 29, 2009 1:53 am

Yep thats what I do. Pretty much in that order...

Well dont forget, under the CMS section, Latest Updates. ... tary09.htm

That can have really valuable, clear, explanations. This when the experiment is working.

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